Time measuring device



TIME'MEASURING DEVICE Filed March 2, 1945 A. J. BUSCH /N|/E/VTOR$-' J WDEHIV B W WH/T/Vf) ATTORNEY Patented Jan. 21, 1947 UNITED STATES PATENTOFFICE M'EAsUnrNG mines Aloysius J Busch, Madison, N J.,.and Joseph W.Dehn, Great Neck, N. Y., and Wiley Whitney, Madison, N. J., assignors toBell Telephone Laboratories; Incorporated, New York, N. Y., acorporation of New York Appiieau'on' 2, 1945, Serial Nb. 580,660"

4 Claims. .1 i

This invention relates to timing and interrupting devices andparticularly to" such devices adapted for use'in controlling the closingand opening of circuits in signaling and other electricalsystems. I

Objects of the invention are the decentralization of interrupterequipment provided in automatic telephone systems for controllingsignaling current, the provision of electronic devices for measuringsignaling intervals in place of power driven interrupt'ers, theprovision of an interrupter which immediately applies ringing currentwhen a trunk with which it is associated requires ringing current, andthe simplification and improvementof timing and interrupting means insignaling and electrical systems;

This invention is a timing and interrupting device comprising a pair ofspace discharge tubes, a pair of relays and means including a condenserassociated with each tube and connected to delay the energization ofthe" tube for a definite and desired predetermined interval of time.More specifically the'condenser associated with one of the tubes ischarged through a resistor until it reaches the breakdown voltagewhereupon the tube is energized to operate the associated relay to startthe charging of the condenser associated with the second tube. Thecondenser associated with the second tube is then charged through aresistor until it reaches the breakdown voltage whereupon the secondtube is energized to operate the associated relay thereby to cause therelease of the relay associated with the first tube and initiate anothertiming cycle. The intervals of time thus measured may be proportioned inany desired manner depending upon the values of the resistances and thecapacity of the condensers; and the intervals may be utilized in anywell-known manner for controlling the opening and closing of electricalcircuits, for instance, those that are used in signaling telephonesubscribers stations. y

A clear and complete explanation of the invention, its features andadvantages will be facilitated by describing its application in theautomatic telephone system shown schematically in the drawing whichforms apart of this specification. The invention is however not limitedin its application tothe system shown but is generally applicable toelectrical systems comprising timing and interrupter devices.

The drawing which consists of a single figure shows schematically anautomatictelephone systern comprising station's A. and B, lines L! andL2, incoming trunk circuit ID, a ringing current generator '40 'andatiming and interrupting device 2 for timing the application of ringingcurrent to a called subscribers line.

In automatic telephone systems it is usual to provide a power drivenrotary ringing machine for applying ringing current at intervals and forintervals of desired duration. In the system disclosed in the drawingthe power driven interrupter device is replaced by a plurality of timingand interrupting devices, each device being common to a group of trunksand comprising a pair of three-element, cold-cathode, gas-filled,discharge tubes and a pair of relays. The telephone system may be amanual system or an automatic system employing any known type ofswitches and switch control. It may for instance be a system, employingswitches of the cross bar type, such as is disclosed in the patent toCarpenter No. 2,093,117, September 14, 1937. v

lhe incoming trunkcircuit IQ is similar to that disclose'din theaforementioned Carpenter patent, only those portions of this trunkcircuit being shown as are necessary for a complete description andunderstanding of applicants invention as applied to signaling in anautomatic telephone system. Relays H, 32 and I3 of the trunk circuit 26correspond respectively to relays 4523, 4524 and 4525 of the trunkcircuit shown in Fig. 45 of the Carpenter patent. I

When a connection has been established between the line Ll of a callingsubscribers station A, through intermediate switching apparatus (whichis represented by broken lines) and incoming trunk circuit It), and whenthe trunk circuit is connected to an incoming marker (not shown), relayI I is operatedin the manner in which relay 4523' is operated in theaforementioned Carpenter patent. I When the called line has been testedand found idle and with relay I l operated, a circuit is closed foroperating the ringing control relay E2 in the same manner in whichrelay4524 is operated in the aforementioned Carpenter patent. Relay [2 locksunder control of relay l3 and partially closes the circuit for applyingringing current to the. called line. After incoming and final switches(which are represented by broken lines) have been operated to extend theconnection to the called line and after the marker has tested thecontinuity of this connection, relay I I is released all in the mannerdescribed in the aforementioned Carpenter patent. The release of relayll closes a circuit for starting the operation of the timing andinterrupter mechanismtzfl. This circuit is traced from the positiveelectrode of a battery B2 or other source of reduired voltagethroughtheinner upper back contact of relay ll, inner upper front contact ofrains a 3 relay l2 and conductor I4 of trunk circuit l0, throughresistors 2| and 22 and condenser 24 to ground. Condenser 24 is thuscharged at a rate depending on its capacity and the resistance ofelements Zl and 22 thereby delaying for a desired interval of time theapplication through resistor 23 to the control anode of tube 25 of ahigh enough voltage to break down the gap between the control anode andcathode of the tube. When breakdown occurs, the right winding of relay26 is energized in series with the main anode and cathode of tube 25 toground at the continuity back contact of relay 26. Relay 26 operatesclosing a locking circuit through its left winding and continuity frontcontact and the back contact of relay 36. The operation of relay 26 alsoconnects ground to resistor 2| to shortcircuit and thereby dischargecondenser 24 and causes the deenergization of tube 25. The operation ofrelay 26 also disconnects ground from the cathode of tube 25, connectsground to the oathode of tube 35, and open the normally closedshort-circuit from resistor 3| to ground thereby starting the chargingof condenser 34 at a rate determined by its capacity and the resistanceof elements 3| and 32. At the end of a desired interval of time, thevoltage built up across condenser 34 and applied through resistor 33 tothe control anode of tube 35 causes breakdown of the gap between thecontrol anode and cathode of the tube. When breakdown occurs, thewinding of relay 36 is energized in series with the main anode andcathode of tube 35 to ground at a front contact of relay 26. Theoperation of relay 38 opens the locking circuit of relay 26 to cause therelease of relay 26. The release of relay 26 disconnects ground from thecathode of tube 35 to cause the deenergization of the tube and therelease of relay 36, and reconnects ground to resistor 3i to shortcircuit and thereby discharge condenser 34. The release of relay 26 alsoreconnects ground to the cathode of tube 25 and disconnects ground fromresistor 21 thereby to again start the charging of condenser 24.

Thus tubes 25 and 35 and relays 2S and 36 are repeatedly alternatelyoperated and released, the intervals of time during which relay 26 isreleased being measured by the charging of condenser 24 and theintervals of time during which relay 26 is operated being measured bythe charging of condenser 34. Ringing current is thus intermittentlytransmitter from generator 49 through a back contact of relay 26,conductor l5, winding of relay [3, outer lower front contact of relayI2, lower back contact of relay H, lower conductor of line L2, throughthe ringer at station B, upper conductor of line L2, outer upper backcontact of relay H and outer upper front contact of relay l2 to ground.A usual ringing cycle consists of a two second ringing interval and afour second silent interval. When the call is answered at station B,relay I3 is operated thereby causing the release of relay i2. Therelease of relay 12 opens the connection between battery .82 andconductor l4 thereby to stop the operation of interrupter 20 unless someother trunk to which the interrupter is common is in the ringingcondition; in which case, the interrupter continues to operate untilcharging voltage is disconnected from conductor M in each and all ofthese trunks. The release of relay l2 also opens the ringing circuit andcloses the talking connection between stations A and B.

The number of trunks to which the interrupter 20 is common depends onthe number of calls thereover during the busy hour; and the number oftrunks is small enough so that it will seldom happen that a second oneof these trunk will require ringing current after a first trunk hasstarted operation of the interrupter and before this first trunk hasopened the ringing circuit due to answer at the called station orabandonment of the call by the calling subscriber. Thus on substantiallyall calls the interrupter immediately supplies ringing current to atrunk which is ready to apply ringing current to a called station.Furthermore since a plurality of such devices are provided in a centraloffice, the failure of one of the devices affects only a small part ofthe calls whereas with ringing current supplied from a single, rotary,ringing machine, failure of the machine prevents the completion of allcalls made while the machine is out of service; and since eachinterrupter 29 consists of only two tubes, two relays, two condensersand two resistance elements, this decentralization of the ringing supplyis attained at a reasonable cost.

What is claimed is: y

i. In combination, a first relay a second relay, a circuit opened by theoperation and closed by the release of said first relay, first andsecond space discharge tubes each having a starting gap and a main gap,said first relay having an operating Winding connected in series withthe main gap of said first tube for energization when the first tube isenergized and said second relay having an operating winding connected inseries with the main gap of said second tube for energization when thesecond tube is energized, a source of electromotive force for energizingsaid tubes, means connecting said source in series with the starting gapof said first tube while said first relay is not operated, meansconnecting said source in series with the starting gap of said secondtube while said first relay is operated, a condenser connected acrossthe starting gap of said first tube V to delay energization of saidfirst tube and first relay for a predetermined interval of time afterthe connection of said source in series with the starting gap of saidfirst tube, a condenser connected across the starting gap of said secondtube to delay energization of said second tube and second relay for apredetermined interval of time after connection of said source in serieswith the starting gap of said second tube, means including anotherwinding of said first relay for holding said first relay operated untilsaid second relay is operated, means short-circuiting the condenserconnected across the starting gap of said second tube while said firstrelay is not operated, and means short-circuiting the condenserconnected across the starting gap of said first tube while said firstrelay is operated.

2. The combination in a time measuring mechanism for alternatelymeasuring first and second predetermined intervals of time of two spacedischarge tubes each comprising a cathode, control anode and main anode,means for applying an energizing potential across the cathode andcontrol anode of the first tube, means comprising a first condenserconnected in parallel with the' cation of said potential, a first relay,means 'connecting an operating winding of said first relay forenergization in series with the main anode of the first tube when saidtube is energized, a second relay, means connecting a winding of saidsecond relay for energization in series with the main anode of thesecond tube when said second tube is energized, means short-circuitingsaid second condenser while said first relay is not operated andshort-circuiting said first condenser while said first relay isoperated, means locking said first relay operated independent of theenergization of said first tube, means effecting the deenergization ofsaid first tube when said first relay operates, means effecting therelease of said first relay when said second relay operates, and meansefiecting the deenergization of said second tube and second relay whensaid first relay releases.

3. The combination in a time measuring mechanism for alternatelymeasuring first and second predetermined intervals of time of two spacedischarge tubes each comprising a cathode, a control anode and a mainanode, a first relay, a second relay, said first relay having anoperating winding connected in series with the main anode of the firsttube and said second relay having an operating winding connected inseries with the main anode of the second tube, means applying anenergizing potential across the oathode and control anode of said firsttube while said first relay is not operated, means applying anenergizing potential across the cathode and control anode of said secondtube while said first relay is operated, a first condenser connected todelay the energization of said first tube and first relay for said firstpredetermined interval of time after application of said energizingpotential to said first tube, a second condenser connected to delay theenergization of said second tube and second relay for said secondpredetermined interval of time after the application of said energizingpotential to said second tube, means comprising contacts of said firstrelay short-circuiting said first condenser while said first relay isoperated and short-circuiting said second condenser while said firstrelay is not operated, means comprising contacts and a second Winding ofsaid first relay for looking said first relay operated independent ofthe energization of said first tube, and means comprising contacts ofsaid second relay for effecting the release of said first relay whensaid second relay operates.

4. A circuit interrupter mechanism comprising first and second spacedischarge tubes each having a cathode and control and main anodes, asource of electromotive force for energizing said tubes, a first relay,said first relay having an operating winding and a locking winding,means including normally closed contacts of said first relay connectingsaid source and said operating winding in series with the cathode andmain anode of said first tube and connecting said source in series withthe cathode and control anode of said first tube, a first condenserconnected in parallel with the cathode and control anode of said firsttube to delay the energization of said first tube and operation of saidfirst relay for a first predetermined interval of time, means includingcontacts of said first relay for closing a circuit for energizing saidlocking winding before the opening of said normally closed contactseffects the deenergization of said first tube and operating winding,means comprising normally open contacts of said first relayshort-circuiting said first condenser while said first relay isoperated, a second relay, means comprising normally open contacts ofsaid first relay connecting said source and an operating winding of saidsecond relay in series with the cathode and main anode of the second oneof said tubes and connecting said source in series with the cathode andcontrol anode of said second tube, a second condenser, means comprisingsaid second condenser connected in parallel with the cathode and controlanode of said second tube to delay the energization of said second tubeand operation of said second relay for a second predetermined intervalof time, means comprising normally closed contacts of said first relayshort-circuiting said second condenser while said first relay is notoperated, means comprising normally closed contacts of said second relayfor effecting the release of said first relay when said second relayoperates, and a circuit alternately closed and opened by said firstrelay.

ALOYSIUS J. BUSCI-I. JOSEPH W. DEHN. WILEY WHITNEY.

